Ring ni Kakero 1

In order to fulfill their dead father's wish, the siblings, Kiku Takane and Ryuuji Takane aim for the champion title of the boxing arena. The sister, Kiku, will act as the trainer while her brother, Ryuuji, will concentrate on the role of the boxer and learn the Boomerang Hook technique. His battle with many rivals has led to the growth and maturity of Ryuuji. The junior high boxing tournament has began and Ryuuji will be fighting his arch-rival, Jun Kenzaki. The battle begins.
(Source: Anime News Network)